No confirmation for a season 4 of Designated Survivor but instead Netflix provides a Korean version of the same.
Designated Survivor is an American political thriller drama series, directed by David Guggenheim. The show is about a man named Tom Kirkman (play by Kiefer Sutherland) who is a low-level Cabinet member but then suddenly becomes the President of the United States after an attack that kills everyone above him in the line of succession.
And now it is him who has to protect the nation and his family from falling apart other than that he also needs to investigate and know what or who caused the attack. The first season premiered in 2016 and the latest season -Season 3 has been released this year in June.
The series first aired on channel ABC for the first two seasons, but later when the show got canceled, a season 3 along with the prior two seasons were made available on Netflix globally.

Netflix did save the show once, but after looking at the number of shows that Netflix has canceled this year, the fans are scared that Netflix might not renew designated Survivor for a season 4. Although Netflix has not confirmed anything, But if Netflix does renew the show for another season we can probably expect it is premiering during the summers next year and no sooner before that.
However, Netflix did announce a Korean adaptation of Designated Survivor, named as “Designated Survivor: 60 days” about a week ago. A brief teaser for this show has already been released as well, making the audience more desperate for the season 4 of the original Designated Survivor. This new series has the same concept as the original show and is expected that it would surely make it easier for the fans while they wait for the 4th season of the Designated Survivor.